First, we show how to greatly restrict the predicate that an adversary can learn in the protocol, to a natural notion of ``only computation leaks''-style leakage. Along the way, we identify a natural security property of garbled circuits called {\em property-enforcing} that may be of independent interest.
Second, we address a complementary direction of reducing the probability that the leakage occurs. We propose a new dual-execution protocol --- with a very light cheating-detection phase and each party garbling $s+1$ circuits --- in which a cheating party learns a bit with probability only $2^{-s}$. Our concrete measurements show approximately $35\%$ reduction in communication for the AES circuit, compared to the best combination of state of the art techniques for achieving the same security notion.
Combining the two results, we achieve a rich continuum of practical trade-offs between efficiency \& security, connecting the covert, dual-execution and full-malicious guarantees.
Category / Keywords: cryptographic protocols / secure two-party computation Original Publication (in the same form): IACR-TCC-2015 Date: received 22 Jan 2015 Contact author: rosulekm at eecs oregonstate edu Available format(s): PDF | BibTeX Citation Version: 20150123:141722 (All versions of this report) Discussion forum: Show discussion | Start new discussion